03 April 2016

The Ghosts of Sawfish Past

I never thought that a few days working in a museum would inspire me. The quiet, ordered presentation of the natural world in a setting locked away from the elements has always lacked what I love most about research and wildlife: being outside, in wild places; the excitement of searching for and eventually seeing live animals; observing and documenting those experiences. Fieldwork is, for me, the most meaningful part of biological research because it is a process of discovery – of the natural behaviour of animals, of the ways in which the fate of animals, habitats and human communities are linked, and of my own strengths and limitations.

A handful of rostra (saws) from young Largetooth Sawfish collected from the Gambia River in 1974. (c) Ruth H. Leeney.
But sitting in the basement of the University Museum of Zoology, Cambridge, I became immersed in a different type of discovery. It was like opening a long-lost, dusty volume filled with stories of expeditions through West Africa. Not from hundreds of years ago, but nonetheless a different era in terms of sawfish populations – the 1970s. What a difference forty years can make

Nigel Downing putting a sawfish into a holding tank, 1975. (c) N. Downing.
In 1974 and 1975, Dr. Nigel Downing conducted a study of sawfishes in the Casamance and Gambia Rivers, in Senegal and The Gambia respectively. He worked in collaboration with local fishermen, asking them to bring him any sawfishes they caught. Back then, sawfishes were no more than a nuisance to local fishers – they entangled and damaged their fishing nets, and had little value at market. They caught a great many, especially during the rainy season when there was clearly an abundance of pups (juvenile sawfish) in both rivers. The fishers usually kept only the rostra (saws), sending the meat to Ghana where dried shark and ray meat was, and still is, popular (international trade in sawfish parts has only been prohibited since 2013). When Nigel’s project was brought to an abrupt close, he was able to bring over 40 sawfish rostra back to Cambridge, where they have since lain unnoticed. Until now. 

Before me were four wooden drawers holding carefully-wrapped layers of tissue paper, which I folded back to reveal bundles of rostra from very young sawfishes.  I have never seen so many sawfish rostra all together in one place. On some, the skin still had a golden iridescence, while others were still encrusted with river mud or bore a solitary glittering fish scale, impaled on a needle-sharp tooth; they seemed like a collection of careworn Christmas decorations. In these museum drawers lie the relics of a time when sawfish saws could be collected by the handful and were worn on the headdresses of the Bijago people of Guinea-Bissau, or placed on the roofs of houses in The Gambia and Senegal to protect families from evil spirits. One of nature's most decadently-decorated animals, and the traditions it inspired, now only a fading memory in most West African societies

In the stillness of the museum’s basement, where all is clean, carefully stored and climate-controlled, I felt a million miles from the dust, mud, burning sun, clamour and stench of fish markets and the general sensory overload that comes hand-in-hand with my usual fieldwork in Africa. But as I eyed the museum treasures, I was transported back in time to a different West Africa: one where rivers teemed with baby sawfish. Fishermen in Guinea-Bissau had described to me how, years ago, they went to the beach at night and speared small sawfish in the shallows by the light of their torch flames. Holding the miniature saws of young sawfish in my hands, I imagined and wondered at such a scene of abundance – a scene that exists no more. 
Juvenile Largetooth Sawfish caught in The Gambia in the 1970s. (c) Nigel Downing.
Nonetheless, these ‘Ghosts of Sawfish Past’ can reveal stories never before documented. Although sawfishes disappeared from much of the West African coast several decades ago (we’re still not sure where, if anywhere, in West Africa they remain), museum collections can tell us much. Which species lived in the Gambia River and which in the Casamance River? Were they closely related to the sawfish found on the other side of the Atlantic, in Florida and the Bahamas, or were they different? Did sawfishes from these two rivers move large distances along the West African coastline, or did they stay close to the areas where they were born? Genetic analysis of the dried cartilage from sawfish saws is now possible, and will answer some of these questions. It may also help researchers to understand whether sawfish populations might be able to recover in West Africa or if, once gone, they are gone forever. I’ll soon be heading back to the mangroves and coasts to continue my search for Africa’s last sawfishes, but with a new respect for the invaluable role museums can play in providing a window to the past. Knowing what has been lost in West Africa, can we redouble our efforts to protect the sawfish populations that remain, before they meet a similar fate? 

Many thanks to Matt Lowe, Collections Manager at UMZC for facilitating access to the collection and to Save Our Seas Foundation for funding my visit to the museum. 
This blog post was originally published on the Save Our Seas Foundation website: http://saveourseas.com/update/the-ghosts-of-sawfish-past/ 

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